St. Petersburg-Clearwater airport officials and the Transportation Security Administration react after a man sneaked onto an empty plane.

Three months ago, a homeless man slipped onto the grounds of St. Petersburg-Clearwater International Airport about 2:45 a.m. He walked to a ramp area, then climbed the stairs onto an empty 737 and parked himself in the 10th row.

A mechanic saw the man board the plane. He called 911 and confronted the man, whom deputies charged with trespassing.

Since then, the Transportation Security Administration has determined how the homeless man may have breached the airport's security. Though neither TSA nor airport officials will say how he got onto the grounds, they say the problem has been fixed.

"The airport has taken corrective actions," said Lauren Stover, a TSA spokeswoman. "There was a vulnerability on the outer perimeter."

The homeless man, Richard N. Moore, 40, pleaded no contest to a trespassing charge last week. He was sentenced to six months of probation, fined about $245, ordered to seek psychological treatment and warned to stay away from the airport.

Moore, who gave court officials an address in Brandon on the day of his sentencing, could not be reached for comment Wednesday.

Pinellas sheriff's officials said Moore initially told them he had no idea how he gained access to the airport. He appeared to be disoriented and told deputies he was taking the antianxiety drug Xanax. He also said he sometimes blacked out and walked in his sleep.

Sheriff's officials said Moore later told them he had climbed over a fence on the west side of the airport property, near the old Turtle Club.

Airport operations manager Tom Jewsbury said in the days after the incident that it would have been impossible for Moore to enter the grounds from that area.

Moore was sopping wet and dirty when he was found, which means he probably had traveled through water to get onto the grounds, said Pat Siracusa of the State Attorney's Office.

"I can't imagine why else he would be wet," he said.

Stover, the TSA spokeswoman, said Moore cooperated with the agency. He later remembered how he got on the grounds and told investigators.

"The TSA, through its investigation, has identified possible entry points and has since worked with the airport to make arrangements to prevent future occurences," said Jewsbury.

Aviation officials said there are multiple layers of security at the airport. In this case, though one layer may have failed, another succeeded when the mechanic noticed Moore board the plane.

At the time of his arrest, Moore told deputies he simply wanted to take a plane ride.